【摘要】 通过对2002年5月采自南海南部11个站位的28个浮游分层拖网样品的定量研究,初步分析了南海南部上层水体中多孔放射虫的组成与分布特征。共鉴定出116属221种多孔放射虫,其中泡沫虫目123种,占总种数的55.7%;罩笼虫目98种,占总种数的44.3%。罩笼虫目在个体数量上占优势,罩笼虫目与泡沫虫目个体数量之比平均达1.73。多孔放射虫的属种组成呈现明显的热带暖水动物群的组合面貌,优势种相当突出,其组成与南海中北部海区及其它低纬度大洋相比存在一定差异,反映了南海南部海区独特的多孔放射虫属种组成特征。多孔放射虫丰度在不同水层中因受到不同环境因素的影响而呈现不同的平面分布趋势,惟一相似之处是高值多出现于西南或东北部海区;在垂直方向上基本呈随深度增加而减小的分布趋势,丰度和属种数最高值均出现于0—50m水层,在50m以深丰度和属种数均明显减少。各站位间简单分异度S变化幅度较大,在75—140种之间;而复合分异度H(s)变化幅度较小,在3.5—4.0之间。总体来说分异度值均比较高,表明南海南部上层水体中多孔放射虫种类多样性程度比较高,种群比较繁盛。更多还原

【Abstract】 A total of 28 plankton tow samples collected from the eleven sites in the southern South China Sea during the monsoon transition from winter to summer in May 2002 were examined to study the composition and distribution characters of modern polycystine radiolarian in the upper 200m layer. Based on identification and statistics, totally 116 genera and 221 species of polycystine radiolarian were found, among of them were 123 Spumellaria and 98 Nassellaria species, accounting for 55.7% and 44.3% of the fauna respectively, while the individual number of Nassellaria was 1.73 times as high as that of Spumellaria. In addition, the composition of radiolarian genera and species showed a significant tropic warm water fauna characteristic. The dominant species in the area were Botryocyrtis scutum, Lithomelissa monoceras, Pterocorys hertwigii, and Tetrapyle octacantha, indicating a special fauna composition characteristic, which was different from the northern and central SCS as well as the other low latitude sea areas. Furthermore, both abundance and diversity for the total radiolarian showed the highest values in the upper 50m layer and decreased with water depth increasing. The horizontal distributions of living polycystine radiolarian in the layers of 0—50m, 50—100m and 100—200m showed different tendences due to different physical and chemical environments, and only had the similar patterns with the highest abundance in the southwest or northeast areas. The simple diversities were variable between 75 and 140 species and the complex diversities between 3.5 and 4.0 in the upper 200m layer of all the sites. The diversities were generally high in all the areas, indicating a high diversity of prosperous polycytine radiolarian fauna during the period of monsoonal transition from winter to summer.更多还原